This invention relates to timed electrical switches, and more particularly to a switching mechanism responsive to a timed electrical switch.
Timing modules are known in the art, and generally include a power input and a power output, a timing mechanism, and a switch responsive to operation of the timing mechanism for controlling supply of power to the power output. The timing mechanism can either be a conventional motor-operated mechanism or a digital electronic timer, for selectively supplying and cutting off power to the timing module power output. Timing modules of this type are relatively inexpensive and reliable, and provide relatively easy operation by a user.
A typical timing module of the type summarized above has a switch mechanism rated for approximately 20 amps of electrical current. Thus, it has not been possible to employ a timing module of this type in a heavier application, such as supplying electrical power to equipment such as water heaters, billboard lights, swimming pool pumps or the like.
The present invention has as its object to adapt a timing module of the type summarized above for use in a heavier application than it otherwise could be employed by direct connection to the load due to the low capacity of the timing module switch. It is another object of the invention to provide a timing device incorporating such a timing module. Yet another object of the invention is to provide a simple and inexpensive timing device which is easily operated by the user, yet which can be employed in relatively heavy applications.
In accordance with the invention, a timing device for connection in an electrical circuit includes a timing module as summarized above, in which the timing module power input is interconnected in the electrical circuit to provide electrical power thereto. A mechanical switch mechanism is connected in the electrical circuit for controlling the supply of power to an electrical load. An actuator mechanism is interposed between the timing module power output and the mechanical switch mechanism for selectively actuating the mechanical switch mechanism in response to electrical power output from the timing module power output, to supply power to the electrical load through the mechanical switch mechanism. The actuator mechanism includes an output member which is movable in response to the supply of electrical power from the timing module power output, and a mechanical actuator arrangement interconnected between the movable output member and the mechanical switch mechanism. The output member and the mechanical actuator arrangement acting on the mechanical switch mechanism in response to electrical power supplied to the power output of the timing module, to control the supply of power in the electrical circuit through the mechanical switch mechanism. The movable output member is defined by the extendable and retractable plunger of a solenoid, which is interconnected with the timing module power output so as to selectively extend and retract the solenoid plunger in response to operation of the switching mechanism of the timing module. The mechanical switch mechanism has a movable switch contact member and a stationary switch contact member, and the mechanical actuator arrangement includes a cam member movable in response to extension and retraction of the solenoid plunger to control the position of the movable switch contact. The cam member is mounted to a pivotable shaft, and an actuating lever is connected between the solenoid plunger and the pivotable shaft for selectively providing pivoting movement of the shaft, and thereby movement of the cam member, in response to extension and retraction of the solenoid plunger. In a preferred form, the electrical circuit in which the timing device is connected is an AC circuit, and the solenoid is DC operated, and an AC to DC power converter is interposed between the timing module power output and the solenoid to convert AC power from the timing module power output to DC power supplied to the solenoid.
The invention further contemplates a method of connecting a timing module in an electrical circuit, substantially in accordance with the foregoing summary.
Various other features, objects and advantages of the invention will be made apparent from the following description taken together with the drawings.